/* * Copyright (c) 2010-2011, The MiCode Open Source Community (www.micode.net) * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package net.micode.notes.data; import android.app.SearchManager; import android.content.ContentProvider; import android.content.ContentUris; import android.content.ContentValues; import android.content.Intent; import android.content.UriMatcher; import android.database.Cursor; import android.database.sqlite.SQLiteDatabase; import android.net.Uri; import android.text.TextUtils; import android.util.Log; import net.micode.notes.R; import net.micode.notes.data.Notes.DataColumns; import net.micode.notes.data.Notes.NoteColumns; import net.micode.notes.data.NotesDatabaseHelper.TABLE; public class NotesProvider extends ContentProvider { // 定义一个静态的UriMatcher对象,用于匹配URI private static final UriMatcher mMatcher; // 创建一个NotesDatabaseHelper实例 private NotesDatabaseHelper mHelper; // 定义一个常量TAG,用于日志记录 private static final String TAG = "NotesProvider"; // 定义一些常量URI,用于匹配不同的数据表或操作 private static final int URI_NOTE = 1; private static final int URI_NOTE_ITEM = 2; private static final int URI_DATA = 3; private static final int URI_DATA_ITEM = 4; private static final int URI_SEARCH = 5; private static final int URI_SEARCH_SUGGEST = 6; // 在静态代码块中初始化mMatcher,添加匹配规则 static { mMatcher = new UriMatcher(UriMatcher.NO_MATCH); mMatcher.addURI(Notes.AUTHORITY, "note", URI_NOTE); mMatcher.addURI(Notes.AUTHORITY, "note/#", URI_NOTE_ITEM); mMatcher.addURI(Notes.AUTHORITY, "data", URI_DATA); mMatcher.addURI(Notes.AUTHORITY, "data/#", URI_DATA_ITEM); mMatcher.addURI(Notes.AUTHORITY, "search", URI_SEARCH); mMatcher.addURI(Notes.AUTHORITY, SearchManager.SUGGEST_URI_PATH_QUERY, URI_SEARCH_SUGGEST); mMatcher.addURI(Notes.AUTHORITY, SearchManager.SUGGEST_URI_PATH_QUERY + "/*", URI_SEARCH_SUGGEST); } // 定义一个常量字符串,用于搜索结果的投影 private static final String NOTES_SEARCH_PROJECTION = ... //省略具体实现 // 定义一个常量字符串,用于搜索查询语句 private static final String NOTES_SNIPPET_SEARCH_QUERY = ... //省略具体实现 @Override public boolean onCreate() { // 创建NotesDatabaseHelper实例并返回true mHelper = NotesDatabaseHelper.getInstance(getContext()); return true; } @Override public Cursor query(Uri uri, String[] projection, String selection, String[] selectionArgs, String sortOrder) { // 根据传入的URI进行匹配,执行相应的数据库查询操作 Cursor c = null; SQLiteDatabase db = mHelper.getReadableDatabase(); String id = null; switch (mMatcher.match(uri)) { // ...省略其他case的处理逻辑... } // 如果Cursor不为空,设置通知URI并返回Cursor if (c != null) { c.setNotificationUri(getContext().getContentResolver(), uri); } return c; } @Override public Uri insert(Uri uri, ContentValues values) { // 根据传入的URI进行匹配,执行相应的数据库插入操作 SQLiteDatabase db = mHelper.getWritableDatabase(); long dataId = 0, noteId = 0, insertedId = 0; switch (mMatcher.match(uri)) { // ...省略其他case的处理逻辑... } // 如果有对应的noteId或dataId,通知相应的URI变化 // ...省略通知逻辑... // 返回新插入数据的URI return ContentUris.withAppendedId(uri, insertedId); } @Override public int delete(Uri uri, String selection, String[] selectionArgs) { // 根据传入的URI进行匹配,执行相应的数据库删除操作 int count = 0; String id = null; SQLiteDatabase db = mHelper.getWritableDatabase(); boolean deleteData = false; switch (mMatcher.match(uri)) { // ...省略其他case的处理逻辑... } // 返回删除的数据条数 return count; } // ...省略其他方法的实现... }